Method for manufacturing semiconductor substrate and method for manufacturing semiconductor device

Abstract

An SOI substrate having a single crystal semiconductor layer with high surface planarity is manufactured. A semiconductor substrate is doped with hydrogen, whereby a damaged region which contains large quantity of hydrogen is formed. After a single crystal semiconductor substrate and a supporting substrate are bonded together, the semiconductor substrate is heated, whereby the single crystal semiconductor substrate is separated in the damaged region. While a heated high-purity nitrogen gas is sprayed on a separation plane of the single crystal semiconductor layer separated from the single crystal semiconductor substrate, laser beam irradiation is performed. By irradiation with a laser beam, the single crystal semiconductor layer is melted, whereby planarity of the surface of the single crystal semiconductor layer is improved and re-single-crystallization is performed.

1. A method for manufacturing a semiconductor device comprising:
 fixing a single crystal semiconductor layer over a glass substrate with a buffer layer interposed therebetween; and 
 while blowing a heated nitrogen gas to heat the single crystal semiconductor layer at temperature of a strain point or lower of the glass substrate, irradiating a part of the single crystal semiconductor layer with a laser beam to melt an upper layer of the single crystal semiconductor layer with a lower layer of the single crystal semiconductor layer left as a single crystal semiconductor and perform re-single-crystallization of the single crystal semiconductor layer to be a single crystal semiconductor having a same crystal orientation as a crystal orientation of the single crystal semiconductor in the lower layer. 
 
   
   
     2. A method for manufacturing a semiconductor device according to  claim 1 , wherein a defect in a portion of a single crystal melted by irradiation with the laser beam is repaired during the re-single-crystallization. 
   
   
     3. A method for manufacturing a semiconductor device according to  claim 1 , wherein the glass substrate is one of a non-alkali glass substrate (product name: AN100), a non-alkali glass substrate (product name: EAGLE2000 (registered trademark)), and a non-alkali glass substrate (product name: EAGLE XG (registered trademark)). 
   
   
     4. A method for manufacturing a semiconductor device according to  claim 1 , wherein the buffer layer has a stacked structure and includes a barrier layer for preventing sodium from entering the single crystal semiconductor layer. 
   
   
     5. A method for manufacturing a semiconductor device according to  claim 1 , wherein the buffer layer has a stacked structure and includes one of a silicon nitride film and a silicon nitride oxide film and an oxide film obtained by oxidizing the single crystal semiconductor substrate. 
   
   
     6. A method for manufacturing a semiconductor device according to  claim 1 , wherein the buffer layer has a stacked structure and includes a bonding layer to be bonded to one of the glass substrate and the single crystal semiconductor substrate. 
   
   
     7. A method for manufacturing a semiconductor device according to  claim 1 , wherein the buffer layer has a stacked structure, and includes a bonding layer bonded to the glass substrate, an insulating film which is in contact with the single crystal semiconductor layer, and a barrier layer for preventing sodium from entering the single crystal semiconductor layer formed between the bonding layer and the insulating film. 
   
   
     8. A method for manufacturing a semiconductor device according to  claim 7 , wherein the insulating film which is in contact with the single crystal semiconductor layer is one of a silicon oxide film and a silicon oxynitride film and an insulating film containing a halogen. 
   
   
     9. A method for manufacturing a semiconductor device according to  claim 1 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppm or less. 
   
   
     10. A method for manufacturing a semiconductor device according to  claim 1 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppb or less. 
   
   
     11. A method for manufacturing a semiconductor device according to  claim 1 , wherein the nitrogen gas is blown from both a front side and a back side of the glass substrate. 
   
   
     12. A method for manufacturing a semiconductor device comprising:
 fixing a single crystal semiconductor layer over a glass substrate with a buffer layer interposed therebetween; and 
 while blowing a heated nitrogen gas to heat the single crystal semiconductor layer at temperature of a strain point or lower of the glass substrate, irradiating a part of the single crystal semiconductor layer with a laser beam to melt an entire layer of the single crystal semiconductor layer overlapping with the irradiated part in a depth direction and perform re-single-crystallization of the single crystal semiconductor layer to be a single crystal semiconductor having a same crystal orientation as a crystal orientation of a single crystal semiconductor in a region of the single crystal semiconductor layer adjacent to the part of the single crystal semiconductor layer irradiated with the laser beam. 
 
   
   
     13. A method for manufacturing a semiconductor device according to  claim 12 , wherein a defect in a portion of a single crystal melted by irradiation with the laser beam is repaired during the re-single-crystallization. 
   
   
     14. A method for manufacturing a semiconductor device according to  claim 12 , wherein the glass substrate is one of a non-alkali glass substrate (product name: AN100), a non-alkali glass substrate (product name: EAGLE2000 (registered trademark)), and a non-alkali glass substrate (product name: EAGLE XG (registered trademark)). 
   
   
     15. A method for manufacturing a semiconductor device according to  claim 13 , wherein the buffer layer has a stacked structure and includes a barrier layer for preventing sodium from entering the single crystal semiconductor layer. 
   
   
     16. A method for manufacturing a semiconductor device according to  claim 12 , wherein the buffer layer has a stacked structure and includes one of a silicon nitride film and a silicon nitride oxide film and an oxide film obtained by oxidizing the single crystal semiconductor substrate. 
   
   
     17. A method for manufacturing a semiconductor device according to  claim 12 , wherein the buffer layer has a stacked structure and includes a bonding layer to be bonded to one of the glass substrate and the single crystal semiconductor substrate. 
   
   
     18. A method for manufacturing a semiconductor device according to  claim 12 , wherein the buffer layer has a stacked structure, and includes a bonding layer bonded to the glass substrate, an insulating film which is in contact with the single crystal semiconductor layer, and a barrier layer for preventing sodium from entering the single crystal semiconductor layer formed between the bonding layer and the insulating film. 
   
   
     19. A method for manufacturing a semiconductor device according to  claim 18 , wherein the insulating film which is in contact with the single crystal semiconductor layer is one of a silicon oxide film and a silicon oxynitride film and an insulating film containing a halogen. 
   
   
     20. A method for manufacturing a semiconductor device according to  claim 12 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppm or less. 
   
   
     21. A method for manufacturing a semiconductor device according to  claim 12 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppb or less. 
   
   
     22. A method for manufacturing a semiconductor device according to  claim 12 , wherein the nitrogen gas is blown from both a front side and a back side of the glass substrate. 
   
   
     23. A method for manufacturing a semiconductor device comprising:
 fixing a single crystal semiconductor layer over a glass substrate with a buffer layer interposed therebetween; 
 while blowing a heated nitrogen gas to heat the glass substrate to which the single crystal semiconductor layer is fixed at temperature of a strain point or lower of the glass substrate, irradiating a part of the single crystal semiconductor layer with a linear laser beam to perform re-single-crystallization of the single crystal semiconductor layer to be a single crystal semiconductor having a same crystal orientation as a crystal orientation of a single crystal semiconductor in a lower layer; and 
 the glass substrate is moved in a direction perpendicular to a longitudinal direction in a region irradiated with the linear laser beam to perform re-single-crystallization and planarization of the single crystal semiconductor layer. 
 
   
   
     24. A method for manufacturing a semiconductor device according to  claim 23 , wherein a defect in a portion of a single crystal melted by irradiation with the laser beam is repaired during the re-single-crystallization. 
   
   
     25. A method for manufacturing a semiconductor device according to  claim 23 , wherein the glass substrate is one of a non-alkali glass substrate (product name: AN100), a non-alkali glass substrate (product name: EAGLE2000 (registered trademark)), and a non-alkali glass substrate (product name: EAGLE XG (registered trademark)). 
   
   
     26. A method for manufacturing a semiconductor device according to  claim 23 , wherein the buffer layer has a stacked structure and includes a barrier layer for preventing sodium from entering the single crystal semiconductor layer. 
   
   
     27. A method for manufacturing a semiconductor device according to  claim 23 , wherein the buffer layer has a stacked structure and includes one of a silicon nitride film and a silicon nitride oxide film and an oxide film obtained by oxidizing the single crystal semiconductor substrate. 
   
   
     28. A method for manufacturing a semiconductor device according to  claim 23 , wherein the buffer layer has a stacked structure and includes a bonding layer to be bonded to one of the glass substrate and the single crystal semiconductor substrate. 
   
   
     29. A method for manufacturing a semiconductor device according to  claim 23 , wherein the buffer layer has a stacked structure, and includes a bonding layer bonded to the glass substrate, an insulating film which is in contact with the single crystal semiconductor layer, and a barrier layer for preventing sodium from entering the single crystal semiconductor layer formed between the bonding layer and the insulating film. 
   
   
     30. A method for manufacturing a semiconductor device according to  claim 29 , wherein the insulating film which is in contact with the single crystal semiconductor layer is one of a silicon oxide film and a silicon oxynitride film and an insulating film containing a halogen. 
   
   
     31. A method for manufacturing a semiconductor device according to  claim 23 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppm or less. 
   
   
     32. A method for manufacturing a semiconductor device according to  claim 23 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppb or less. 
   
   
     33. A method for manufacturing a semiconductor device according to  claim 23 , wherein the nitrogen gas is blown from both a front side and a back side of the glass substrate. 
   
   
     34. A method for manufacturing a semiconductor device comprising:
 fixing a single crystal semiconductor layer over a glass substrate with a buffer layer interposed therebetween; 
 while blowing a heated nitrogen gas to heat the glass substrate to which the single crystal semiconductor layer is fixed at temperature of a strain point or lower of the glass substrate, irradiating a part of the single crystal semiconductor layer with a linear laser beam to melt an entire layer of the single crystal semiconductor layer overlapping with the irradiated part in a depth direction and perform re-single-crystallization of the single crystal semiconductor layer to be a single crystal semiconductor having a same crystal orientation as a crystal orientation of a single crystal semiconductor in a region adjacent to the part of the single crystal semiconductor layer irradiated with the laser beam; and 
 the glass substrate is moved in a direction perpendicular to a longitudinal direction in a region irradiated with the linear laser beam to perform re-single-crystallization and planarization of the single crystal semiconductor layer. 
 
   
   
     35. A method for manufacturing a semiconductor device according to  claim 34 , wherein a defect in a portion of a single crystal melted by irradiation with the laser beam is repaired during the re-single-crystallization. 
   
   
     36. A method for manufacturing a semiconductor device according to  claim 34 , wherein the glass substrate is one of a non-alkali glass substrate (product name: AN100), a non-alkali glass substrate (product name: EAGLE2000 (registered trademark)), and a non-alkali glass substrate (product name: EAGLE XG (registered trademark)). 
   
   
     37. A method for manufacturing a semiconductor device according to  claim 34 , wherein the buffer layer has a stacked structure and includes a barrier layer for preventing sodium from entering the single crystal semiconductor layer. 
   
   
     38. A method for manufacturing a semiconductor device according to  claim 34 , wherein the buffer layer has a stacked structure and includes one of a silicon nitride film and a silicon nitride oxide film and an oxide film obtained by oxidizing the single crystal semiconductor substrate. 
   
   
     39. A method for manufacturing a semiconductor device according to  claim 34 , wherein the buffer layer has a stacked structure and includes a bonding layer to be bonded to one of the glass substrate and the single crystal semiconductor substrate. 
   
   
     40. A method for manufacturing a semiconductor device according to  claim 34 , wherein the buffer layer has a stacked structure, and includes a bonding layer bonded to the glass substrate, an insulating film which is in contact with the single crystal semiconductor layer, and a barrier layer for preventing sodium from entering the single crystal semiconductor layer formed between the bonding layer and the insulating film. 
   
   
     41. A method for manufacturing a semiconductor device according to  claim 40 , wherein the insulating film which is in contact with the single crystal semiconductor layer is one of a silicon oxide film and a silicon oxynitride film and an insulating film containing a halogen. 
   
   
     42. A method for manufacturing a semiconductor device according to  claim 34 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppm or less. 
   
   
     43. A method for manufacturing a semiconductor device according to  claim 34 , wherein concentration of an oxygen gas in the nitrogen gas is 30 ppb or less. 
   
   
     44. A method for manufacturing a semiconductor device according to  claim 34 , wherein the nitrogen gas is blown from both a front side and a back side of the glass substrate.